Zhou Yanying, Fan Xiaomei, Jiao Tingying, Li Wenzhou, Chen Panpan, Jiang Yiming, Sun Jiahong, Chen Yixin, Chen Pan, Guan Lihuan, Wen Yajie, Huang Min, Bi Huichang
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen 518102, China.
Acta Pharm Sin B. 2021 Jan;11(1):89-99. doi: 10.1016/j.apsb.2020.06.016. Epub 2020 Jul 4.
Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury, and its prognosis depends on the balance between hepatocyte death and regeneration. Sirtuin 6 (SIRT6) has been reported to protect against oxidative stress-associated DNA damage. But whether SIRT6 regulates APAP-induced hepatotoxicity remains unclear. In this study, the protein expression of nuclear and total SIRT6 was up-regulated in mice liver at 6 and 48 h following APAP treatment, respectively. knockdown in AML12 cells aggravated APAP-induced hepatocyte death and oxidative stress, inhibited cell viability and proliferation, and downregulated CCNA1, CCND1 and CKD4 protein levels. knockdown significantly prevented APAP-induced NRF2 activation, reduced the transcriptional activities of and and the mRNA levels of , , and . Furthermore, SIRT6 showed potential protein interaction with NRF2 as evidenced by co-immunoprecipitation (Co-IP) assay. Additionally, the protective effect of P53 against APAP-induced hepatocytes injury was -dependent. The mRNA was significantly down-regulated in mice. activated the transcriptional activity of and exerted interaction with SIRT6. Our results demonstrate that SIRT6 protects against APAP hepatotoxicity through alleviating oxidative stress and promoting hepatocyte proliferation, and provide new insights in the function of SIRT6 as a crucial docking molecule linking P53 and NRF2.
对乙酰氨基酚（APAP）过量是药物性肝损伤的主要原因，其预后取决于肝细胞死亡与再生之间的平衡。据报道，沉默调节蛋白6（SIRT6）可防止氧化应激相关的DNA损伤。但SIRT6是否调节APAP诱导的肝毒性仍不清楚。在本研究中，APAP处理后6小时和48小时，小鼠肝脏中核SIRT6和总SIRT6的蛋白表达分别上调。AML12细胞中的SIRT6敲低加剧了APAP诱导的肝细胞死亡和氧化应激，抑制了细胞活力和增殖，并下调了CCNA1、CCND1和CKD4蛋白水平。SIRT6敲低显著阻止了APAP诱导的NRF2激活，降低了HO-1和NQO1的转录活性以及GCLC、GCLM、HO-1和NQO1的mRNA水平。此外，免疫共沉淀（Co-IP）分析证明SIRT6与NRF2存在潜在的蛋白相互作用。此外，P53对APAP诱导的肝细胞损伤的保护作用是SIRT6依赖性的。SIRT6基因敲除小鼠中P53 mRNA显著下调。P53激活了SIRT6的转录活性并与SIRT6相互作用。我们的结果表明，SIRT6通过减轻氧化应激和促进肝细胞增殖来保护机体免受APAP肝毒性的影响，并为SIRT6作为连接P53和NRF2的关键对接分子的功能提供了新的见解。
